Clinical features in adults with congenital disorders of glycosylation type Ia (CDG-Ia).

Congenital disorders of glycosylation (CDG) are a group of metabolic disorders resulting from defective synthesis of N-linked oligosaccharides. CDG-Ia is the most common of the 21 known types defined by defects in different steps of the synthetic pathway. An increasing number of American adults with CDG-Ia are being recognized but little is documented on the morbidity and mortality in this population. These adults have moderate mental retardation, ataxia, retinitis pigmentosa, peripheral neuropathy, kyphoscoliosis, and endocrinopathies. Four adults with CDG-Ia, ages 19-36 years old are presented. All are active, dysarthric conversant adults with moderate cognitive impairment. They are ataxic and wheelchair dependent, however, only the oldest man shows significant muscle atrophy. All have diagnosed peripheral neuropathy. Three of four remain on anticonvulsants with only occasional seizures, none have had stroke-like episodes since their teen years. Their skeletal issues include significant kyphoscoliosis, joint contractures, and osteopenia. Retinitis pigmentosa and myopia complicate their functional vision. The women do not menstruate and the men have small testes resulting from hypogonadotropic hypogonadism. Documentation of clinical complications and successful management strategies in adults with CDG will improve their quality of life and allow more informed prognostic discussions with families of younger affected individuals.